These anomalies, which are confined to males, are eight times less prevalent than posterior urethral valves. In many aspects they constitute a continuum of urethral pathology while also being distinct entities in their own right. It is difficult to define the point at which the urethral dilatation proximal to anterior urethral valves constitutes a diverticulum, and similarly the point at which an extensive diverticulum becomes a megalourethra.
- Anterior urethral valves (AUV) are a much less common cause of infravesical obstruction, with as much potential morbidity as posterior urethral valves. As classically described, these take the form of either a fenestrated diaphragmatic membrane or a mucosal cusp arising from the ventral wall of the urethra. Because anterior urethral valves are occasionally found at the distal end of a diverticulum, it is unknown whether the anomaly developed primarily as a diverticulum with undermining of the distal urethra and secondary development of valvular obstruction or early valvular obstruction that resulted in proximal maldevelopment of the urethra and spongiosum.
Is a rare congenital anomaly characterized by abnormal dilatation of the penile urethra in the absence of any evident obstruction. It may be associated with lack of corpus spongiosum or with complete absence of the corpora cavernosa. In such cases the penis amounts to little more than a floppy sac comprised of skin externally and urethral mucosa internally.
It shares some of the characteristics of a urethral diverticulum but includes more extensive and uniform involvement of the urethra.
The classification of fusiform and scaphoid types reflects the severity of the defect and the resultant effect on the corpus spongiosum and corpora cavernosum.
- The scaphoid form results from deficiency or absence of the ventral corpora spongiosum.
- A fusiform megalourethra also affects the dorsal sponge and corpora cavernosa.
- More recently, Adamson and Burge have described a third type with all corpora intact.
The cause of megalourethra remains somewhat controversial.
- Stephens postulated that a delay in cannulization of the distal epithelial core might lead to obstruction and proximal dilation.
- Others have suggested that embryologic arrest of the mesoderm investing the urethral folds influences the development of the corpora and erectile tissue.
Megalourethra is often associated not only with other urorectal anomalies such as imperforate anus, prune-belly syndrome, and urethral valves, but also with varying degrees of uropathy.
Diagnosis is often suspected on physical examination, particularly if the child is seen to void. The urethral meatus may be normally placed but pathologic.
Treatment centers on reconstruction of the urethra and corpora spongiosum using common principles of hypospadias repair. The scaphoid urethra can be opened longitudinally using the better dorsal and lateral tissue.
Cowper's glands are paired structures found along the posterolateral aspect of the proximal urethra, located on either side of the urethra. The main glands lie within the urogenital diaphragm, and accessory glands are located more distally along the bulbous urethra. Each gland is drained by a duct that courses medially and posteriorly through the corpus spongiosum to empty side-by-side in the bulbar urethra.
Cowper’s gland cysts (syringocoeles)
Urethral atresia and agenesis must be included in the differential diagnosis of renal anomalies and bilateral hydronephrosis diagnosed in utero. Unfortunately, unless there is some other egress for the urine to escape the bladder, such as a patent urachus or an urorectal communication, these lesions are not compatible with renal development.
Management will depend on the specific anomaly and the amount of renal function salvaged by alternative urinary drainage.
Another rare set of urethral anomalies is duplication.
These rare anomalies may be sagittal or collateral.
Urethral strictures in children are the result of three etiologic possibilities: congenital, infectious, or traumatic (iatrogenic or noniatrogenic).
Whether congenital or acquired, such strictures are generally mild and respond well to endoscopic urethrotomy. Formal urethroplasty is rarely required.
Urethral Stricture in females:
The condition is uncommon but occurs in boys aged 6 years and upward, with presenting features that include dysuria, penile discomfort and urethral discharge or urethral bleeding – usually consisting of no more than spotting on the underclothes.
Attempts to culture a specific organism are unrewarding.
In the absence of other features, cystourethroscopy is not indicated, as it rarely makes a practical contribution to clinical management. However, when urethroscopy is performed, the findings are characterised by erythema of the anterior and bulbar urethra, with a granular appearance and strands of fibrinous exudate.
There is no specific treatment and the condition is self-limiting, although it sometimes runs a protracted course.